When I got my Mossberg all that there was around was a plastic stock one and I can't deal with a plastic stock. So while I was waiting on the wood stock I took it apart and the barrel channel was about like what you have. Haven't touched it other than remove it. My thought at the time was do to the barrel what you did, but that much glass would cost to much for me. Bondo is a good idea. I suspect that had you got the bondo in and a couple layer's of tape under the barrel you might have been able to float the barrel without taking it down later. I would assume that release agent on the tape would keep the bondo from sticking to the barrel. So how heavy is that bondo anyway? You have me thinking I might try that with the plastic stock as I still have it! That rod sounds like a good idea too. I saw a wood stock gun that was done for a friend and it has a push rod bedded into the stock. Guy talked him into it. But I don't think it helped a thing, the wood stock was a laminated! Nice video's! How did you get the recoil pad off without messing up the stock? I would think two bars of lead would be heavy. I have lots around for casting bullet's and each bar weight's 1#!